The Kristen Stewart Cheating Scandal of 2012 just chalked up another casualty -- the marriage of Liberty Ross and Rupert Sanders, TMZ reports.

Ross has filed paper in Los Angeles Superior Court to divorce Sanders, who was caught by paparazzi making out with Stewart last year. Ross is seeking joint custody of the couple's two children, TMZ says. Ross is also asking for spousal support and attorney's fees.

Sanders has also requested joint custody of the kids, TMZ says.

Sanders' affair with Stewart, whom he directed in "Snow White and the Huntsman," made headlines last year and prompted the breakup of "Twilight" lovers Stewart and Robert Pattinson. They have since reconciled.

TMZ says Ross and Sanders were trying to repair their marriage via counseling. Their kids are aged 5 and 7.